Dandong, alias Red Oriental City, is a prefecture-level city in Liaoning Province, located in the southeast of Liaoning Province, on the west side of Yalu River, facing North Korea across the river in the east and the Yellow Sea in the south. Dandong has jurisdiction over 3 municipal districts, 1 autonomous county and 2 county-level cities, with a total area of 1.52 million square kilometers. Dandong is located in the border of the motherland and has been a military fortress for generations.
Place code is a proprietary two-dimensional code used by people to enter key places, and an independent identification code generated by the platform for key places. By scanning the place code, all the people entering and leaving the place can be registered automatically, and the health card status of the people entering and leaving the place at that time will also be displayed. Local codes can prevent and control the epidemic more accurately.